The present invention relates to a data transfer system which transfers, bit by bit, serial data sent from first equipment, such as a numerical controller, to predetermined bits of a predetermined address of a RAM provided in second equipment, such as an electric power control circuit of a machine tool.
In general, a serial data transfer system is employed for data transfer between separated equipment with a view to reducing the number of transmission lines used. When the equipment on the receiving side processes received data by means of a microcomputer, it is necessary to convert the received serial data into parallel data and temporarily store it in a RAM or the like. In such an instance, it is customary in the prior art to perform the serial parallel conversion upon each reception of serial data of a predetermined number of bits, for example, eight bits, and store the converted data in the RAM. Accordingly, in the case where each bit of the serial data is given a specific significance, there will be caused, at the receiving side, a time lag in recognition corresponding to the time needed for sending the predetermined number of bits of serial data.